Integrated evaluation of water quality in semi-arid Eurasian rivers using the methods of single-factor and water quality index
Year: 2026
Type: article
Abstract: Water quality degradation poses a critical challenge to the sustainable use of global freshwater resources, especially in semi-arid regions where water scarcity is severe. However, little attention has been paid to the water quality and critical contaminants of semi-arid rivers, and effective methods of water quality evaluation are deficient in these vulnerable regions. This study conducted integrated water quality evaluation by combining the single-factor (SF) and water quality index (WQI) methods in two large semi-arid Eurasian rivers (i.e., the Irtysh River and Ili River) between China, Kazakhstan and Russia. Meanwhile, the critical contaminants were identified based on WQI and a multivariate statistical method. The integrated evaluation exhibited an overall “good” water quality, yet revealed potential hazards from nitrogen and organic pollution. Significant water quality degradation was detected during the flood season, particularly in the middle and lower reaches of these two rivers. Total suspended solids (TSS) were the most critical factor inducing water quality degradation in the Irtysh River and Ili River. An optimal minimal water quality index (WQImin) model that consists of TSS, CODMn, NO3-N, NH4-N, and WT, yielded improved predictive accuracy when parameter weights were considered. Our study emphasized the urgent need to conduct integrated evaluation of water quality in semi-arid regions. We proposed that the TSS deserved special attention in managing water quality of semi-arid rivers. Moreover, this study confirmed the regional transferability of the WQImin model, providing a novel perspective on cost-effective water quality evaluation in data-limited and drought-prone regions.
Source: Ecological Indicators
Authors: Chong Sang, Jun Wang, Yan Guo, Congxin Xie, Qiong Zhou
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,650
OpenAlex ID: W7127580910